Move to the body of this page
Miniature & small ball bearings

Measurement methods

The general principles for verifying the dimensions and runout of rolling ball bearings are specified in JIS B 1515-2.
The overview of the method of measuring the actual dimensions and runout is shown below.


Dimensions related

1. Actual bore diameter (ds) Fig. 8-1
2. Actual outer diameter (Ds) Fig. 8-2
3. Actual inner ring width (Bs) Fig. 8-3
4. Actual outer ring width (Cs) Fig. 8-4

Runout related

1. Perpendicularity of inner ring side surface with respect to the inner diameter axis (Sd) Fig. 8-5
2. Perpendicularity of outer ring outer diameter surface with respect to the side surface (SD) Fig. 8-6
3. Radial runout of inner ring (Kia) Fig. 8-7
4. Radial runout of outer ring (Kea) Fig. 8-8
5. Axial runout of inner ring (Sia) Fig. 8-9
6. Axial runout of outer ring (Sea) Fig. 8-10

Remark: [ ] is the expression in previous JIS.

Measure at different angles in the radial plane.
Bore diameter (ds)
Fig. 8-1

Measure at different angles in the radial plane.
Outer diameter (Ds)
Fig. 8-2

Turn the inner ring once and measure.
Inner ring width (Bs)
Fig. 8-3

Turn the outer ring once and measure.
Outer ring width (Cs)
Fig. 8-4

Read the indicator while rotating the inner ring once.
Perpendicularity of the inner ring side (Sd)
Fig. 8-5

Read the indicator while rotating the outer ring once.
Perpendicularity of the outer ring outer diameter surface (SD)
Fig. 8-6

Apply a load to the inner ring and read the indicator while rotating once.
Radial runout of inner ring (Kia)
Fig. 8-7

Apply a load to the outer ring and read the indicator while rotating once.
Radial runout of outer ring (Kea)
Fig. 8-8

Apply a load to the inner ring and read the indicator while rotating once.
Axial runout of inner ring (Sia)
Fig. 8-9

Apply a load to the outer ring and read the indicator while rotating once.
Axial runout of outer ring (Sea)
Fig. 8-10

Support / Contact

For product-related inquiries, please contact us using the form below.

Page Top